This invention relates to an improved apparatus for drying, oxidizing, and grinding scrap textile glass fibers and removing foreign material from the ground fibers to produce a recyclable dry, flowable powder. The present invention improves upon the process and apparatus of U.S. Pat. No. 4,353,725. The process and apparatus of the '725 patent recycles scrap glass by removing the binder, preheating and grinding the glass scrap. The '725 invention utilizes a rotary drum which receives heat transfer media and scrap glass at one end. As the drum rotates, the heat transfer media and scrap glass flow toward the outlet end. At the outlet end the preheated fines overflow from a discharge unit and are fed to a glass end process.
The '725 apparatus is acceptable for the recycling of dry, coarse, discontinuous glass fibers but encounters problems if used to process wet, fine, continuous glass fibers such as those used in textile reinforcement products. The process of recycling wet textile glass products creates a large amount of steam and water vapor, generated as the moisture evaporates from the scrap product. The steam and water vapor interfere with the ability of the firing tube of the '725 apparatus to properly and efficiently preheat the heat transfer media. Further, problems are encountered when attempting to process wet textile scrap with the '725 apparatus in that the scrap accumulates in the inlet of the rotary drum causing the inlet to plug and resulting in shut-down of the recycling system. Finally, another problem is encountered with the discharge unit of the rotary drum of the '725 invention. Because the discharge unit is incorporated in a side wall of the rotary drum, ground glass fines tend to accumulate at the discharge end of the rotary drum, preventing an even flow of fines through the discharge.
The improved apparatus of the present invention is intended to overcome the problems encountered by the '725 apparatus when used to process wet textile scrap glass. The present invention provides an apparatus for use in processing scrap textile glass fibers which drys, oxidizes, grinds, and screens the material into a dry, flowable powder. The present invention is comprised of a cylindrical drum rotatable about its axis. The drum includes an inlet frustum into which the wet textile scrap material and preheated media are placed for mixing within the drum. The frustum eliminates the clogging problems encountered with the '725 apparatus. The cylindrical drum also incorporates an unique separating system for removing glass particulate fines from the rotating drum and recycling the heat transfer media to the media hopper for reheating. A series of rod grates positioned proximate the outlet of the rotatable cylinder provides for a smooth flow of ground glass fines from the cylinder without creating the undersirable accumulation of fines at the discharge end of the rotating drum.
The present invention is intended to provide an apparatus which will dry, oxidize, and grind wet scrap textile glass fibers into a dry, flowable powder.
The apparatus of the present invention is intended to reduce clogging problems at the inlet of the rotatable drum.
The apparatus of the present invention is intended to facilitate the removal of dry particulate fines from the discharge end of the rotatable drum after processing.